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Information and Research RESEARCH NOTE Services Number 11, 2000–01 ISSN 1328-8016

Plague Locust Threat to Australian Agriculture Introduction Plague Locusts The Australian Plague Throughout this year the Australian The Australian plague locust Locust Commission (APLC) Plague Locust Commission (APLC) (Chortoicetes terminifera) is one of The APLC was established in 1974 (funded by the Federal, NSW, three major locust pests in and became operational in 1976 to Victorian, South Australian and Australia. The plague locust is the co-ordinate the monitoring and Queensland Governments) has most recurring and potentially control of plague locusts, including issued bulletins warning of a damaging of the three. The other the spur-throated and migratory potential plague locust disaster for two are the spur-throated locust locusts, considered a threat to Australian agriculture this Spring. (Austracis guttulosa) and the interstate rural industries, although migratory locust (Locusta the APLC may be invited to assist if These warnings have alerted migratoria). Locust outbreaks occur requested. Western Australia and farmers and government to the need from time to time across Australia Tasmania are not APLC members. to identify and monitor risk areas in depending on climatic factors. the months leading up to the locust The APLC is funded and comprised hatching season from September to Outbreaks of plague locusts often of the Commonwealth Government November. Grain crops are originate in semi-arid and arid zones (50 per cent) and the governments particularly at risk. of Australia. During Summer 1999- of NSW (32.5 per cent), Victoria 2000 and Autumn 2000 these areas (10 per cent), South Australia (5 per The APLC predicts a major received exceptional rainfall that cent) and Queensland (2.5 per cent). outbreak of plague locusts allowed locust levels to build up to representing significant threats to The 1999–2000 budget allocation plague proportions and provided grain crops in large areas of NSW, for APLC was $3.14 million. ideal conditions for the laying of the South Australia and parts of eggs, despite control measures. The main functions of the APLC are Victoria. Queensland is rated a preventative control using chemical moderate risk (see map over page). Plague locust eggs laid in Autumn sprays, monitoring and forecasting The Agriculture Protection Board in lie dormant in the resting stage in contributor states where interstate Western Australia has identified and through Winter. Hatchings begin migrations are likely to occur. been monitoring potentially massive when moisture and temperature outbreaks of locust activity from conditions are right in the Spring. Moora to Esperance. It takes from 4 to 6 weeks for locust Major locust outbreaks causing nymphs to reach fledging stage and Brad Hinton Economics, Commerce and damage to crops were recorded in another 2 weeks to adult maturation Industrial Relations Group Western Australia in 1990, in enabling migratory flight. Information and Research western NSW in 1992 and in parts The main danger to agriculture Services of South Australia in 1992, 1993 occurs where crops are still green. and 1997. This current locust threat 3 October 2000 Crop damage from bands of nymphs is envisaged to be considerably Views expressed in this Research Note and migratory locusts can be worse than these. Current crop are those of the author and do not significant. Even crops approaching damage estimates are difficult to necessarily reflect those of the ripeness can be attacked, Information and Research Services forecast but Agriculture WA says particularly in the small green area and are not to be attributed to the that potential damage in that state below the grain head just prior to Department of the Parliamentary alone could be up to $200 million Library. Research Notes provide the readiness for harvesting. without control measures. concise analytical briefings on issues During daytime, plague locusts may of interest to Senators and Members. The hatching season usually begins As such they may not canvass all of feed and migrate up to a distance of in September in warmer areas the key issues. Advice on legislation 10-20 kilometres. At night they may or legal policy issues contained in this (northern South Australia and north- fly hundreds of kilometres paper is provided for use in western NSW) through to late depending on wind conditions. parliamentary debate and for related October in cooler areas (south-east parliamentary purposes. This paper is Predicting where and how far locust NSW and Victoria). Egg hatchings not professional legal opinion. swarms will migrate to is uncertain. in Western Australia are expected to  Commonwealth of Australia accelerate in early October. Preventative Control Current Control Activities North-west Victoria is a high risk area. The Victorian Government Preventative control aims to control Landholders are largely responsible pledged an additional $1 million on locust populations before they reach for locust control on their own September 13 to fund aerial outbreak levels and includes the properties using ground control spraying. The risk of locust monitoring, forecasting and equipment. Local councils and migrations from NSW and South treatment of infested areas. The farmer groups often work together Australia is a significant danger. main control agent is a chemical to organise some control measures. insecticide, principally fenitrothion. The South Australian Government The optimum time to spray is about The APLC will target high-risk has allocated $6 million for the a fortnight after hatching when areas for aerial spraying of plague 2000 Locust Control Program. In locust nymphs aggregate into dense locusts across member states to addition, local councils will be bands. Chemical spraying that limit potential interstate migrations. reimbursed up to 95 per cent from targets adult locusts in aerial Government Responses the South Australian Local swarms may occur at a later stage Government Disaster Fund to help depending on location and The Federal Government provides defray locust control costs. In environmental limitations. Locust half the total funding for the August the State Government bands and swarms in pastoral areas Australian Plague Locust announced a $1 per hectare rebate are easier to aerial spray because of Commission within the Department scheme for farmers using approved reduced limitations. of Agriculture, Fisheries and and certified chemicals for locust Forestry. Commonwealth funding control. APLC research in conjunction with for 1999–2000 was $1.6 million. the CSIRO has looked at biological locust control using a naturally occurring fungus that will be tested this season in some sensitive areas. Monitoring and Forecasting Monitoring is by ground surveys in Eastern Australia and by reporting of locust activity by farmers and agricultural field officers. Long distance migrations are recorded by eight light traps in Eastern Australia. The light traps attract locust numbers and estimates are made on the size of Agriculture WA has a Locust the swarms. The light traps are The NSW Department of Response Plan and, with farmers, is located in Oodnadatta and Agriculture and the Rural Lands gearing up for a $30 million Dulkannina in South Australia, at Protection Board assist in plague campaign over 2 million hectares. Fowlers Gap and White Cliffs in locust control. Chemicals have been NSW, and at Nooyeah Downs, made available to farmers and Conclusion Birdsville, Julia Creek, and financed from levies to the Noxious A significant threat to crop Longreach in Queensland. Insect Destruction Account. Aerial production exists from plague Forecasting possible locust plague spraying by APLC and landholders locusts in the coming months locations and monitoring has already begun in western NSW. although chemical spraying and developments are important for Queensland's Department of Natural crop maturity may mitigate disaster. preventative control. Locust surveys Resources is monitoring the south- (Map used with permission from and reports, meteorological data and west of the state where a moderate APLC from their website at: quantitative modelling are used by risk has been forecast. http://www.affa.gov.au/aplc ) APLC in a computerised Decision Support System.